7 Blade Fan

[markandson]

I have 3 different fans from the cars and 2.2 engine that I have.
Five blade with a positive "bump" where it mounts to the water pump,which is the one that came off of the 2.2.
Five blade with a depression where it mounts to the water pump, which came off of one of the 1.9's.
Seven blade with a slightly larger hub and a depression at the water pump mount. So, is there and advantage/disadvantage to using the 7 blade fan? What engine did these originally come from, it has OPEL molded right into the plastic.

[namba209]

Oh Boy, Jeff this could be a hard one, but it depends on the reason for changing out the fan. And it could actually make no difference, depending on blade pitch and surface area on each one. So to make it easier, greater pitch/area would be more air flow and more load on the engine. Lesser pitch/area would be less air flow and less drag on the motor. Thae application on each fan origionly, I don't know. Members with more knowledge/experience on the engine than I could help there. HTH.

[greensmurf20]

i believe the 7 blade fans were from the AC equipped cars.

[soybean]

I had always heard that the 5 bladed fans were for the earlier models and the 7 bladed ones were for the later model (low comperssion) engines. As Ron said the 5 bladed would be less air flow and less drag on the motor. The 75s had a fan clutch that would help lessen the drag on the motor even more. I don't remember how many blades they have, but I believe they too were 5 bladed. I have 2 in the shop I will look at tomorrow. Jarrell

[manta73wi]

My three Mantas all have 7 bladed fans, but they're all different. The '73 has a black plastic fan, the '74 parts car has an off white plastic fan which appears to differ only in color to the '73, and the '75 has an off white plastic fan with a larger hub and is the cluth fan type. They all seem to cool just fine, but I don't have any experience with a 5 blade to compare.
-Jeff W

[bmetsoldier]

Jeff, I have the same fans that you do, being we both have the same engine. I found I would have to change my water pump and pully in order for any of my five blade fans to work. I think the pump from a 75 Manta was suggested. I didn't want to do that, mostly because I have time restraints, so I just went with a electric fan. It fit real easy up in the battery compartment and from what I hear it will gain a couple of HP. I don't know what kind of car the fan came out of but I seen another car with the same fan. I will attach a picture. It also runs very quit and blows really hard.

Arnold

[bmetsoldier]

Screwed up on attaching.

[markandson]

Actually the fan that came on the 2.2 was a 5 blade fan. The 7 blade came out of a 1.9 car, which was a 72, but who knows who did what in the past. The 72 did not have A/C. I am sure I have enough stuff to mix and match to find something that will work on the 2.2. I have a 3 core radiator for it so maybe going with a 5 blade will be good enough and save a little HP for eating horse meat.

[opelbits]

7 blade fans are very noisy. I had one on my GT (although it came off my old 74 Manta which did have a/c) and the change to a five blade dropped engine compartment noise considerably.